• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1573-1576
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• 2003

The quality of bundles is closely related with the apparent thickness. Especially the variation of apparent thickness of bundle determines the qualify of the plane structure made or the bundle such as surface evenness, pore size, and the shape of air-gap, etc.,. This study is dealing with the development of a new measuring system of the thickness of bundle or cross-section by determining the size of the shadow of the object covered by a laser slit beam. Also the measured signal is characterized in terms of the correlogram, the irregularity in wavelength. The correlogram for the irregularity of several sample types could be represented by a sinusoidal function with exponentially decaying amplitude. Moreover, influence of the measuring speed on the signal and the characteristic differences according to the different types of bundle are investigated.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.1
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• pp.31-39
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• 1995

We have various methods of measurement for a safety diagnosis of outworn structure, but these methods to find a variation of structure are not convincible with it's exactness and confidence. We have to lay out a scheme for a solution of these problems and improve a visibility of result. In this study, we studied a optimized solution for close-range photogrammetry to offer the more reliable method compare to conventional method and to improve it's confidens and visibility of output. For obtaining these effects, we manufactured the plane models and curved surface ones each devided into two types, normal case and obilique case. In this way, we got a optimum solution to increase a confidence level and visibility of photogrammetry. And actually, this study will be a good way to measure a variation of structures.

• Computational Structural Engineering
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• v.7 no.2
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• pp.147-153
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• 1994

A method for shape design sensitivity analysis for axisymmetric shells of general shapes is developed. The basic approach is to divide the structures into many segments : For each of the segments, the formula for a shallow arch or shell can be applied and the results assembled. To interconnect those segments, the existing sensitivity formula, obtained for a variation only in the direction perpendicular to the plane on which the structure is mapped, has been extended to include a variation normal to the middle surface. The method follows the adjoint variable approach based on the material derivative concept as established in the literature. Numerical examples are taken to illustrate the method and the applicability to practical design problems.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.273-276
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• 1995

In vitro propagation of Neoregeria carorinae 'Tricolor' was achieved by using immature flowers and lateral buds, and the plantlets from tissue culture were transplanted and cultivated in greenhouse. The picking times of explants to decrease disappearance of stripes, and in vivo the growth and flowering of regenerated plantlets as influenced by in vivo healed nun were investigated. The normal plantlet were obtained at a frequency of 67%, in the culture of immature flowers picked at 4 weeks after flower bud differentiation, while all leaf stripes disappeared in the culture of immature flowers picked 1 and 5 weeks after flower bud differentiation. In vivo growth of plantlet from immature flower buds was better than those from lateral buds, and the flowering of 27.8% showed in the greenhouse culture of plantlet from immature culture, but the plantlets from lateral buds did not flower at all. The plantlets rooted on the medium with 0.5 mg/L IBA were the most favorable in green house culture, and the kinds and concentrations of auxin in vitro did not have any influence on variation of plane cultured in greenhouse.

• Journal of Mechanical Science and Technology
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• v.14 no.3
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• pp.320-330
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• 2000

It is desirable to perform nondestructive evaluation (NDE) to assess material properties and part homogeneity because the manufacturing of carbon/carbon brake disks requires complicated and costly processes. In this work several ultrasonic techniques were applied to carbon/carbon brake disks (322mm ad, 135mm id) for the evaluation of spatial variations in material properties that are attributable to the manufacturing process. In a large carbon/carbon disk manufactured by chemical vapor infiltration (CYI) method, the spatial variation of ultrasonic velocity was measured and found to be consistent with the densification behavior in CYI process. Low frequency (e.g., 1-5MHz) through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity. Images based on both the amplitude and the time-of-flight of the transmitted ultrasonic pulse showed significant variation in the radial direction. The radial variations in ultrasonic velocity and attenuation were attributed to a density variation caused by the more efficient densification of pitch impregnation near the id and od and by the less efficient densification away from the exposed edged of the disk. Ultrasonic velocities in the edges of the disk. Ultrasonic velocities in the thickness direction were also measured as a function of location using dry-coupling transducers ; the results were consistent with the densification behavior. However, velocities in the in-plane directions (circumferential and radial) seemed to be affected more by the relative contents of fabric and chopped fiber, and less by the void content.

• Plant Journal
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• v.18 no.4
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• pp.48-57
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• 2023

In this study, I discussed a way of the improved operation criteria to detect combustion instability in advance F-Class Gas Turbine, which adopts lean pre-mixed combustion system. The data of 16 blades path temperature thermocouple installed radially at the gas Turbine exit were collected to analyze the variation of individual blade path temperature. The cumulative variation in individual blade path temperature for one week under normal combustion conditions was confirmed to be up to 26℃. On the other hand, in the event of combustion instability, the symptoms of increased temperature variations in the individual thermocouple were mostly seen from a few days ago. Based on the results of this study, it is deemed appropriate to inspect and maintain in Ulsan Thermal Power Gas Turbine when the individual blade path temperature exceeds 50℃ of the cumulative variation for 10 days.

• The KSFM Journal of Fluid Machinery
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• v.2 no.3 s.4
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• pp.17-23
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• 1999

In the present numerical analysis, investigation of the effect of blade loadings from design shape on the slip factor variation was studied. Both the Eckardt radial bladed impeller and the backswept impeller were analyzed. In addition, a new design of the blade profile was arbitrarily attempted to generate a center-loading pattern in the original backswept impeller. Three dimensional compressible Navier-Stokes flow analysis with the Baldwin-Lomax turbulence model was applied to get the numerical slip factor at each impeller exit plane using the mass-averaging technique. The numerical slip (actors are in good agreement with the experimental ones and the Wiesner's slip factors deviate further from the numerical and experimental ones in both backswept impellers. Deviation angles and meridional channel loadings are found in no relation with the trend of change of the slip factor. Blade-to-blade loadings in midspan location are, however, found to have a direct relationship, especially at the sections where maximum loadings we to be expected. That information can be utilized in establishing an improved expression for slip factors in the future.

• The Journal of the Petrological Society of Korea
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• v.17 no.2
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• pp.95-107
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• 2008

The Carved Buddhist Triad on Rock-cliff in Sinarnri (Treasure No. 680) consists of biotite granodiorite, which were positively carved on fore and west planes of four subvertical cliffs by two joint sets of NE-SW and NNW-SSE directions. The cliffs are $N50^{\circ}E\;85^{\circ}SE$ in fore plane, $N25^{\circ}W\;90^{\circ}$ in west plane, $N40{\sim}50^{\circ}E\; 82{\sim}85^{\circ}NW$, back plane, $N20^{\circ}W\;75^{\circ}SW$ in east plane, which are parallel to two joint sets of NE-SW and NNW-SSE directions in geology around it. The chemical index of alteration ranges 60.3 to 62.0 from the major elements in the rock that was weathered into producing kaolin minerals from alteration of feldspars and biotite. The Buddhist image has been deteriorated into joints, brown rusts, discolorations and granular disintegrations by such deterioration causes as deformation, moisture, temperature variation and microorganic living. The moisture, which leaks from groundwater in the rock, dissolve to decompose minerals.

• Korean Journal of Materials Research
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• v.2 no.6
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• pp.389-397
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• 1992

Workability and aging behavior of Mg-Li-Al alloys hate been investigated with variation of Li and Al contents. It was found that ${\alpha}$(HCP) + ${\beta}$(BCC) two phase structure reveals better workability than ${\alpha}$(HCP) single phase structure. Increase of workability is attributed to the additional slip on pyramidal and prism planes besides the slip on basal plane of HCP Mg. Workability of ${\alpha}$+${\beta}$ two phase structure is improved with increased amount of Al. Among alloys studied in the present study, reduction limit up to 62 % was obtained for Mg-8.08Li-4.26Al. MgL$i_2$Al(${\theta}$) aging precipitation was observed in ${\alpha}$+ ${\beta}$ two phase structure, while it was not in a single phase structure. Result of microhardness reveals peak hardness for ${\alpha}$ +${\beta}$ two phase structure due to $\theta$ precipitate in ${\theta}$ phase. In ${\alpha}$+${\beta}$ two phase Mg-Li-Al alloys, hardness increased with increasing amount of Al. It is believed that addition of Al raised the amount Al partition in u phase and ${\theta}$ precipitation in ${\beta}$ phase.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.89-93
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• 1992

We experimented cutting characteristics-cutting force, behavior of chip, surface roughness-under low temperature, which generated by liquid nitrogen(77K). The results obtained are as follows; 1) The workpice is became to-195 .deg. C in 5, minutes, and in cooled cutting, cutting force bycooled workpices is stronger than normal temperature condition. Chip thickness is decreasing comparative toN.C and shear angle in shear plane is in creasing. 2) Chip formation becomes long or short tubular chips in turning SXM440, SNCM21 steel, when cutting speed is low and cutting temperatre is cooled condition, but in the STS304 steel the variation of c formations isn't known to. 3) In C.C, surface roughness of workpices is better than N.C and found to make more the crat wearthan N.C 4) It is possible to detect the behavior of chip by monitoring the maximum amplitude of gai value of cutting force.